Denitration catalysts used for treating nitrogen oxides contained in exhaust gas generally include titania having vanadium supported thereon. Denitration catalysts have been designed in related arts to increase the supporting amount of the catalyst and the vanadium concentration in the catalyst, in order to enhance the denitration capability thereof.
The present inventors have prepared denitration catalysts by a method of allowing titania to be supported on a carrier of a ceramic fiber sheet or a carrier which is molded from a ceramic fiber sheet and processed into honeycomb shape, and immersing the carrier in a vanadium solution to impregnate the carrier with vanadium, thereby allowing the carrier to support vanadium, or a method of preparing a slurry by adding vanadium into a titania slurry containing titania powder suspended in silica sol, and allowing the same carrier as above to support the slurry, as described in PTL 1 below.